Surgical stapler with reversible polarity

ABSTRACT

A method for resetting a stapling apparatus includes providing an apparatus with a cam member in a fired position. A circuit of the apparatus is then changed from a first polarity state to a second polarity state. A motor of the apparatus is then activated to rotate the cam member from a fired position back to a home position while the circuit is in the second polarity state.

PRIORITY

This application is a continuation of U.S. patent application Ser. No.15/914,358, entitled “Surgical Stapler with Reversible Polarity,” filedMar. 7, 2018, and issued as U.S. Pat. No. 10,517,602 on Dec. 31, 2019,which is a continuation-in-part of U.S. patent application Ser. No.14/751,231, entitled “Surgical Stapler with Reversible Motor,” filedJun. 26, 2015, and issued as U.S. Pat. No. 10,456,134 on Oct. 29, 2019,the disclosure of which is incorporated by reference herein.

BACKGROUND

In some surgical procedures (e.g., colorectal, bariatric, thoracic,etc.), portions of a patient's digestive tract (e.g., thegastrointestinal tract and/or esophagus, etc.) may be cut and removed toeliminate undesirable tissue or for other reasons. Once the tissue isremoved, the remaining portions of the digestive tract may be coupledtogether in an end-to-end anastomosis. The end-to-end anastomosis mayprovide a substantially unobstructed flow path from one portion of thedigestive tract to the other portion of the digestive tract, withoutalso providing any kind of leaking at the site of the anastomosis.

One example of an instrument that may be used to provide an end-to-endanastomosis is a circular stapler. Some such staplers are operable toclamp down on layers of tissue, cut through the clamped layers oftissue, and drive staples through the clamped layers of tissue tosubstantially seal the layers of tissue together near the severed endsof the tissue layers, thereby joining the two severed ends of theanatomical lumen together. The circular stapler may be configured tosever the tissue and seal the tissue substantially simultaneously. Forinstance, the circular stapler may sever excess tissue that is interiorto an annular array of staples at an anastomosis, to provide asubstantially smooth transition between the anatomical lumen sectionsthat are joined at the anastomosis. Circular staplers may be used inopen procedures or in endoscopic procedures. In some instances, aportion of the circular stapler is inserted through a patient'snaturally occurring orifice.

Examples of circular staplers are described in U.S. Pat. No. 5,205,459,entitled “Surgical Anastomosis Stapling Instrument,” issued Apr. 27,1993; U.S. Pat. No. 5,271,544, entitled “Surgical Anastomosis StaplingInstrument,” issued Dec. 21, 1993; U.S. Pat. No. 5,275,322, entitled“Surgical Anastomosis Stapling Instrument,” issued Jan. 4, 1994; U.S.Pat. No. 5,285,945, entitled “Surgical Anastomosis Stapling Instrument,”issued Feb. 15, 1994; U.S. Pat. No. 5,292,053, entitled “SurgicalAnastomosis Stapling Instrument,” issued Mar. 8, 1994; U.S. Pat. No.5,333,773, entitled “Surgical Anastomosis Stapling Instrument,” issuedAug. 2, 1994; U.S. Pat. No. 5,350,104, entitled “Surgical AnastomosisStapling Instrument,” issued Sep. 27, 1994; and U.S. Pat. No. 5,533,661,entitled “Surgical Anastomosis Stapling Instrument,” issued Jul. 9,1996; and U.S. Pat. No. 8,910,847, entitled “Low Cost Anvil Assembly fora Circular Stapler,” issued Dec. 16, 2014. The disclosure of each of theabove-cited U.S. Patents is incorporated by reference herein.

Some circular staplers may include a motorized actuation mechanism.Examples of circular staplers with motorized actuation mechanisms aredescribed in U.S. Pub. No. 2015/0083772, entitled “Surgical Stapler withRotary Cam Drive and Return,” published Mar. 26, 2015, now abandoned;U.S. Pub. No. 2015/0083773, entitled “Surgical Stapling Instrument withDrive Assembly Having Toggle Features,” published Mar. 26, 2015, issuedas U.S. Pat. No. 9,936,949 on Apr. 10, 2018; U.S. Pat. No. 9,907,552,entitled “Control Features for Motorized Surgical Stapling Instrument,”issued Mar. 6, 2018; and U.S. Pat. No. 9,713,469, entitled “SurgicalStapler with Rotary Cam Drive,” issued Jul. 25, 2017. The disclosure ofeach of the above-cited U.S. Patents and Patent Publications isincorporated by reference herein.

While various kinds of surgical stapling instruments and associatedcomponents have been made and used, it is believed that no one prior tothe inventor(s) has made or used the invention described in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a perspective view of an exemplary circular stapler;

FIG. 2 depicts a perspective view of the circular stapler of FIG. 1 ,with a battery pack removed from a handle assembly and an anvil removedfrom a stapling head assembly;

FIG. 3 depicts a perspective view of the anvil of the circular staplerof FIG. 1 ;

FIG. 4 depicts another perspective view of the anvil of FIG. 3 ;

FIG. 5 depicts an exploded side elevational view of the anvil of FIG. 3;

FIG. 6 depicts a perspective view of the stapling head assembly of thecircular stapler of FIG. 1 ;

FIG. 7 depicts an exploded perspective view of the stapling headassembly of FIG. 6 ;

FIG. 8 depicts an exploded perspective view of the circular stapler ofFIG. 1 , with portions of the shaft assembly shown separately from eachother;

FIG. 9 depicts a perspective view of the handle assembly of the circularstapler of FIG. 1 , with a housing half omitted to reveal internalcomponents of the handle assembly;

FIG. 10 depicts a perspective view of a bracket of the handle assemblyof FIG. 9 ;

FIG. 11 depicts a perspective view of an indicator member of the handleassembly of FIG. 9 ;

FIG. 12A depicts a perspective view of an anvil actuation assembly ofthe circular stapler of FIG. 1 , an actuation rod in a first position;

FIG. 12B depicts a perspective view of the anvil actuation assembly ofFIG. 12A, with the actuation rod moved to a second position to engagethe bracket of FIG. 10 ;

FIG. 12C depicts a perspective view of the anvil actuation assembly ofFIG. 12A, with the actuation rod moved to a third position to retractthe bracket of FIG. 10 proximally;

FIG. 12D depicts a perspective view of the anvil actuation assembly ofFIG. 12A, with a safety trigger pivoted from a first position to asecond position;

FIG. 12E depicts a perspective view of the anvil actuation assembly ofFIG. 12A, with a firing trigger pivoted from a first position to asecond position;

FIG. 13 depicts a perspective view of a stapling head actuation assemblyof the circular stapler of FIG. 1 ;

FIG. 14 depicts a perspective view of a cam follower of the staplinghead actuation assembly of FIG. 13 ;

FIG. 15 depicts another perspective view of the cam follower of FIG. 14;

FIG. 16 depicts a perspective view of a rotary cam of the stapling headactuation assembly of FIG. 13 ;

FIG. 17 depicts another perspective view of the rotary cam of FIG. 16 ;

FIG. 18A depicts a side elevational view of the stapling head actuationassembly of FIG. 13 , with the rotary cam in a first angular positionand the cam follower in a first pivotal position;

FIG. 18B depicts a side elevational view of the stapling head actuationassembly of FIG. 13 , with the rotary cam in a second angular positionand the cam follower in a second pivotal position;

FIG. 19A depicts a perspective view of the rotary cam of FIG. 16 , arocker member, and a stop switch, with the rotary cam in a first angularposition and the rocker member in a first pivotal position;

FIG. 19B depicts a perspective view of the rotary cam of FIG. 16 , therocker member of FIG. 19A, and the stop switch of FIG. 19A, with therotary cam in a fourth angular position and the rocker member in asecond pivotal position;

FIG. 20A depicts a schematic end view of the rotary cam of FIG. 16 , thecam follower of FIG. 14 , and the rocker member of FIG. 19A, with therotary cam in the first angular position, the cam follower in the firstpivotal position, and the rocker member in the first pivotal position;

FIG. 20B depicts a schematic end view of the rotary cam of FIG. 16 andthe cam follower of FIG. 14 , with the rotary cam in the second angularposition, the cam follower in the second pivotal position, and therocker member of FIG. 19A in the first pivotal position;

FIG. 20C depicts a schematic end view of the rotary cam of FIG. 16 andthe cam follower of FIG. 14 , with the rotary cam in a third angularposition, the cam follower in the second pivotal position, and therocker member of FIG. 19A in the first pivotal position;

FIG. 20D depicts a schematic end view of the rotary cam of FIG. 16 , thecam follower of FIG. 14 , and the rocker member of FIG. 19A, with therotary cam in a fourth angular position, the cam follower in a thirdpivotal position, and the rocker member in a second pivotal position;

FIG. 21A depicts a cross-sectional side view of the anvil of FIG. 3positioned within a first section of a digestive tract and the staplinghead assembly of FIG. 6 positioned in a second section of the digestivetract, with the anvil separated from the stapling head assembly;

FIG. 21B depicts a cross-sectional side view of the anvil of FIG. 3positioned within the first section of the digestive tract and thestapling head assembly of FIG. 6 positioned in the second section of thedigestive tract, with the anvil secured to the stapling head assembly;

FIG. 21C depicts a cross-sectional side view of the anvil of FIG. 3positioned within the first section of the digestive tract and thestapling head assembly of FIG. 6 positioned in the second section of thedigestive tract, with the anvil retracted toward the stapling headassembly to thereby clamp tissue between the anvil and the stapling headassembly;

FIG. 21D depicts a cross-sectional side view of the anvil of FIG. 3positioned within the first section of the digestive tract and thestapling head assembly of FIG. 6 positioned in the second section of thedigestive tract, with the stapling head assembly actuated to sever andstaple the clamped tissue;

FIG. 21E depicts a cross-sectional side view of the first and secondsections of the digestive tract of FIG. 21A joined together at anend-to-end anastomosis;

FIG. 22 depicts a detailed side view of a portion of an exemplaryalternative circular stapler, shown with a portion of the body removedto show internal components.

FIG. 23 depicts a flowchart showing steps of an exemplary method ofresetting the circular stapler of FIG. 1 or FIG. 22 ;

FIG. 24 depicts a flowchart showing steps of an exemplary alternativemethod of resetting the circular stapler of FIG. 1 or FIG. 22 ;

FIG. 25A depicts a schematic end view of the rotary cam of FIG. 16 , thecam follower of FIG. 14 , and the rocker member of FIG. 19A, with therotary cam in the fourth angular position, the cam follower in the firstpivotal position, and the rocker member in the second pivotal position;

FIG. 25B depicts a schematic end view of the rotary cam of FIG. 16 andthe cam follower of FIG. 14 , with the rotary cam in the third angularposition, the cam follower transitioning toward the second pivotalposition, and the rocker member of FIG. 19A in the first pivotalposition;

FIG. 25C depicts a schematic end view of the rotary cam of FIG. 16 andthe cam follower of FIG. 14 , with the rotary cam in the second angularposition, the cam follower in the second pivotal position, and therocker member of FIG. 19A in the first pivotal position;

FIG. 25D depicts a schematic end view of the rotary cam of FIG. 16 , thecam follower of FIG. 14 , and the rocker member of FIG. 19A, with therotary cam in the first angular position, the cam follower in the firstpivotal position, and the rocker member in a second pivotal position;

FIG. 26 depicts a flowchart showing steps of another exemplaryalternative method of resetting the circular stapler of FIG. 1 or FIG.22 ;

FIG. 27 depicts a flowchart showing steps of another exemplaryalternative method of resetting the circular stapler of FIG. 1 or FIG.22 ;

FIG. 28 depicts a perspective view of an exemplary alternative batterypack that may be used to reset the circular stapler of FIG. 1 ;

FIG. 29A depicts an exemplary control circuit that may be incorporatedinto the circular stapler of FIG. 1 , with the battery pack of FIG. 2inserted in the stapler, with a firing switch in an open state, and witha pair of stop switches in a first polarity state;

FIG. 29B depicts the control circuit of FIG. 29A, with the battery packof FIG. 2 inserted in the stapler, with the firing switch in a closedstate, and with the pair of stop switches in the first polarity state;

FIG. 29C depicts the control circuit of FIG. 29A, with the battery packof FIG. 2 inserted in the stapler, with the firing switch in the closedstate, and with the pair of stop switches in a second polarity state;

FIG. 29D depicts the control circuit of FIG. 29A, with the battery packof FIG. 2 inserted in the stapler, with the firing switch in the openstate, and with the pair of stop switches in the second polarity state;

FIG. 29E depicts the control circuit of FIG. 29A, with the battery packof FIG. 28 inserted in the stapler, with the firing switch in the openstate, and with the pair of stop switches in the second polarity state;

FIG. 29F depicts the control circuit of FIG. 29A, with the battery packof FIG. 28 inserted in the stapler, with the firing switch in the closedstate, and with the pair of stop switches in the second polarity state;

FIG. 29G depicts the control circuit of FIG. 29A, with the battery packof FIG. 28 inserted in the stapler, with the firing switch in the closedstate, and with the pair of stop switches in the first polarity state;

FIG. 29H depicts the control circuit of FIG. 29A, with the battery packof FIG. 28 inserted in the stapler, with the firing switch in the openstate, and with the pair of stop switches in the first polarity state;

FIG. 30A depicts a schematic end view of the rotary cam of FIG. 16 , thecam follower of FIG. 14 , and the rocker member of FIG. 19A, with therotary cam in the fourth angular position, the cam follower in the thirdpivotal position, and the rocker member in the second pivotal position;and

FIG. 30B depicts a schematic end view of the rotary cam of FIG. 16 , thecam follower of FIG. 14 , and the rocker member of FIG. 19A, with therotary cam in the first angular position, the cam follower in the firstpivotal position, and the rocker member in the first pivotal position.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

I. Overview of Exemplary Circular Stapling Surgical Instrument

FIGS. 1-2 depict an exemplary surgical circular stapling instrument (10)that may be used to provide an end-to-end anastomosis between twosections of an anatomical lumen such as a portion of a patient'sdigestive tract. Instrument (10) of this example comprises a handleassembly (100), a shaft assembly (200), a stapling head assembly (300),and an anvil (400). Handle assembly (100) comprises a casing (110)defining an obliquely oriented pistol grip (112). In some versions,pistol grip (112) is perpendicularly oriented. In some other versions,pistol grip (112) is omitted. Handle assembly (110) further includes awindow (114) that permits viewing of a movable indicator needle (526) aswill be described in greater detail below. In some versions, a series ofhash marks, colored regions, and/or other fixed indicators arepositioned adjacent to window (114) in order to provide a visual contextfor indicator needle (526), thereby facilitating operator evaluation ofthe position of needle (526) within window (114). Various suitablealternative features and configurations for handle assembly (112) willbe apparent to those of ordinary skill in the art in view of theteachings herein.

Instrument (10) of the present example further includes a battery pack(120). Battery pack (120) is operable to provide electrical power to amotor (160) in pistol grip (112) as will be described in greater detailbelow. Battery pack (120) is removable from handle assembly (100). Inparticular, as shown in FIGS. 1-2 , battery pack (120) may be insertedinto a socket (116) defined by casing (110). Once battery pack (120) isfully inserted in socket (116), latches (122) of battery pack (120) mayresiliently engage interior features of casing (110) to provide a snapfit. To remove battery pack (120), the operator may press latches (122)inwardly to disengage latches (122) from the interior features of casing(110) then pull battery pack (120) proximally from socket (116). Itshould be understood that battery pack (120) and handle assembly (100)may have complementary electrical contacts, pins and sockets, and/orother features that provide paths for electrical communication frombattery pack (120) to electrically powered components in handle assembly(100) when battery pack (120) is inserted in socket (116). It shouldalso be understood that, in some versions, battery pack (120) isunitarily incorporated within handle assembly (100) such that batteryback (120) cannot be removed from handle assembly (100).

Shaft assembly (200) extends distally from handle assembly (100) andincludes a preformed bend. In some versions, the preformed bend isconfigured to facilitate positioning of stapling head assembly (300)within a patient's colon. Various suitable bend angles or radii that maybe used will be apparent to those of ordinary skill in the art in viewof the teachings herein. In some other versions, shaft assembly (200) isstraight, such that shaft assembly (200) lacks a preformed bend. Variousexemplary components that may be incorporated into shaft assembly (100)will be described in greater detail below.

Stapling head assembly (300) is located at the distal end of shaftassembly (200). As shown in FIGS. 1-2 and as will be described ingreater detail below, anvil (400) is configured to removably couple withshaft assembly (200), adjacent to stapling head assembly (300). As willalso be described in greater detail below, anvil (400) and stapling headassembly (300) are configured to cooperate to manipulate tissue in threeways, including clamping the tissue, cutting the tissue, and staplingthe tissue. A knob (130) at the proximal end of handle assembly (100) isrotatable relative to casing (110) to provide precise clamping of thetissue between anvil (400) and stapling head assembly (300). When asafety trigger (140) of handle assembly (100) is pivoted away from afiring trigger (150) of handle assembly (100), firing trigger (150) maybe actuated to thereby provide cutting and stapling of the tissue.

A. Exemplary Anvil

In the following discussion of anvil (400), the terms “distal” and“proximal” (and variations thereof) will be used with reference to theorientation of anvil (400) when anvil (400) is coupled with shaftassembly (200) of instrument (10). Thus, proximal features of anvil(400) will be closer to the operator of instrument (10); while distalfeatures of anvil (400) will be further from the operator of instrument(10).

As best seen in FIGS. 3-5 , anvil (400) of the present example comprisesa head (410) and a shank (420). Head (410) includes a proximal surface(412) that defines a plurality of staple forming pockets (414). Stapleforming pockets (414) are arranged in two concentric annular arrays. Insome other versions, staple forming pockets (414) are arranged in threeor more concentric annular arrays. Staple forming pockets (414) areconfigured to deform staples as the staples are driven into stapleforming pockets (414). For instance, each staple forming pocket (414)may deform a generally “U” shaped staple into a “B” shape as is known inthe art. As best seen in FIG. 4 , proximal surface (412) terminates atan inner edge (416), which defines an outer boundary of an annularrecess (418) surrounding shank (420).

Shank (420) defines a bore (422) and includes a pair of pivoting latchmembers (430) positioned in bore (422). As best seen in FIG. 5 , eachlatch member (430) includes a “T” shaped distal end (432), a roundedproximal end (434), and a latch shelf (436) located distal to proximalend (434). “T” shaped distal ends (432) secure latch members (430)within bore (422). Latch members (430) are positioned within bore (422)such that distal ends (434) are positioned at the proximal ends oflateral openings (424), which are formed through the sidewall of shank(420). Lateral openings (424) thus provide clearance for distal ends(434) and latch shelves (436) to deflect radially outwardly from thelongitudinal axis defined by shank (420). However, latch members (430)are configured to resiliently bias distal ends (434) and latch shelves(436) to radially inwardly toward the longitudinal axis defined by shank(420). Latch members (430) thus act as retaining clips. This allowsanvil (400) to be removably secured to a trocar (330) of stapling headassembly (300) as will be described in greater detail below. It shouldbe understood, however, that latch members (436) are merely optional.Anvil (400) may be removably secured to a trocar (330) using any othersuitable components, features, or techniques.

In addition to or in lieu of the foregoing, anvil (400) may be furtherconstructed and operable in accordance with at least some of theteachings of U.S. Pat. Nos. 5,205,459; 5,271,544; 5,275,322; 5,285,945;5,292,053; 5,333,773; 5,350,104; 5,533,661; and/or 8,910,847, thedisclosures of which are incorporated by reference herein. Still othersuitable configurations will be apparent to one of ordinary skill in theart in view of the teachings herein.

B. Exemplary Stapling Head Assembly

As best seen in FIGS. 6-7 , stapling head assembly (300) of the presentexample is coupled to a distal end of shaft assembly (200) and comprisesa tubular casing (310) housing a slidable staple driver member (350). Acylindraceous inner core member (312) extends distally within tubularcasing (310). Tubular casing (310) is fixedly secured to an outer sheath(210) of shaft assembly (200), such that tubular casing (310) serves asa mechanical ground for stapling head assembly (300).

Trocar (330) is positioned coaxially within inner core member (312) oftubular casing (310). As will be described in greater detail below,trocar (330) is operable to translate distally and proximally relativeto tubular casing (310) in response to rotation of knob (130) relativeto casing (110) of handle assembly (100). Trocar (330) comprises a shaft(332) and a head (334). Head (334) includes a pointed tip (336) and aninwardly extending proximal surface (338). Shaft (332) thus provides areduced outer diameter just proximal to head (334), with surface (338)providing a transition between that reduced outer diameter of shaft(332) and the outer diameter of head (334). While tip (336) is pointedin the present example, tip (336) is not sharp. Tip (336) will thus noteasily cause trauma to tissue due to inadvertent contact with tissue.Head (334) and the distal portion of shaft (332) are configured forinsertion in bore (422) of anvil (420). Proximal surface (338) and latchshelves (436) have complementary positions and configurations such thatlatch shelves (436) engage proximal surface (338) when shank (420) ofanvil (400) is fully seated on trocar (330). Anvil (400) is thus securedto trocar (330) through a snap fit due to latch members (430).

Staple driver member (350) is operable to actuate longitudinally withintubular casing (310) in response to activation of motor (160) as will bedescribed in greater detail below. Staple driver member (350) includestwo distally presented concentric annular arrays of staple drivers(352). Staple drivers (352) are arranged to correspond with thearrangement of staple forming pockets (414) described above. Thus, eachstaple driver (352) is configured to drive a corresponding staple into acorresponding staple forming pocket (414) when stapling head assembly(300) is actuated. It should be understood that the arrangement ofstaple drivers (352) may be modified just like the arrangement of stapleforming pockets (414) as described above. Staple driver member (350)also defines a bore (354) that is configured to coaxially receive coremember (312) of tubular casing (310). An annular array of studs (356)project distally from a distally presented surface surrounding bore(354).

A cylindraceous knife member (340) is coaxially positioned within stapledriver member (350). Knife member (340) includes a distally presented,sharp circular cutting edge (342). Knife member (340) is sized such thatknife member (340) defines an outer diameter that is smaller than thediameter defined by the inner annular array of staple drivers (352).Knife member (340) also defines an opening that is configured tocoaxially receive core member (312) of tubular casing (310). An annulararray of openings (346) formed in knife member (340) is configured tocomplement the annular array of studs (356) of staple driver member(350), such that knife member (340) is fixedly secured to staple drivermember (350) via studs (356) and openings (346). Other suitablestructural relationships between knife member (340) and stapler drivermember (350) will be apparent to those of ordinary skill in the art inview of the teachings herein.

A deck member (320) is fixedly secured to tubular casing (310). Deckmember (320) includes a distally presented deck surface (322) definingtwo concentric annular arrays of staple openings (324). Staple openings(324) are arranged to correspond with the arrangement of staple drivers(352) and staple forming pockets (414) described above. Thus, eachstaple opening (324) is configured to provide a path for a correspondingstaple driver (352) to drive a corresponding staple through deck member(320) and into a corresponding staple forming pocket (414) when staplinghead assembly (300) is actuated. It should be understood that thearrangement of staple openings (322) may be modified just like thearrangement of staple forming pockets (414) as described above. Itshould also be understood that various structures and techniques may beused to contain staples within stapling head assembly (300) beforestapling head assembly (300) is actuated. Such structures and techniquesthat are used to contain staples within stapling head assembly (300) mayprevent the staples from inadvertently falling out through stapleopenings (324) before stapling head assembly (300) is actuated. Varioussuitable forms that such structures and techniques may take will beapparent to those of ordinary skill in the art in view of the teachingsherein.

As best seen in FIG. 6 , deck member (320) defines an inner diameterthat is just slightly larger than the outer diameter defined by knifemember (340). Deck member (320) is thus configured to allow knife member(340) to translate distally to a point where cutting edge (342) isdistal to deck surface (322).

In addition to or in lieu of the foregoing, stapling head assembly (300)may be further constructed and operable in accordance with at least someof the teachings of U.S. Pat. Nos. 5,205,459; 5,271,544; 5,275,322;5,285,945; 5,292,053; 5,333,773; 5,350,104; 5,533,661; and/or 8,910,847,the disclosures of which are incorporated by reference herein. Stillother suitable configurations will be apparent to one of ordinary skillin the art in view of the teachings herein.

C. Exemplary Shaft Assembly

FIG. 8 shows various components of shaft assembly (200), which couplescomponents of stapling head assembly (300) with components of handleassembly (100). In particular, and as noted above, shaft assembly (200)includes an outer sheath (210) that extends between handle assembly(100) and tubular casing (310). In the present example, outer sheath(210) is rigid and includes a preformed curved section as noted above.

Shaft assembly (200) further includes a trocar actuation rod (220) and atrocar actuation band assembly (230). The distal end of trocar actuationband assembly (230) is fixedly secured to the proximal end of trocarshaft (332). The proximal end of trocar actuation band assembly (230) isfixedly secured to the distal end of trocar actuation rod (220). Itshould therefore be understood that trocar (330) will translatelongitudinally relative to outer sheath (210) in response to translationof trocar actuation band assembly (230) and trocar actuation rod (220)relative to outer sheath (210). Trocar actuation band assembly (230) isconfigured to flex such that trocar actuation band assembly (230) mayfollow along the preformed curve in shaft assembly (200) as trocaractuation band assembly (230) is translated longitudinally relative toouter sheath (210). However, trocar actuation band assembly (230) hassufficient column strength and tensile strength to transfer distal andproximal forces from trocar actuation rod (220) to trocar shaft (332).Trocar actuation rod (220) is rigid. A clip (222) is fixedly secured totrocar actuation rod (220) and is configured to cooperate withcomplementary features within handle assembly (100) to prevent trocaractuation rod (220) from rotating within handle assembly (100) whilestill permitting trocar actuation rod (220) to translate longitudinallywithin handle assembly (100). Trocar actuation rod (220) furtherincludes a coarse helical threading (224) and a fine helical threading(226). Details regarding the movement of trocar actuation rod (220) willbe described in greater detail below.

Shaft assembly (200) further includes a stapling head assembly driver(240) that is slidably received within outer sheath (210). The distalend of stapling head assembly driver (240) is fixedly secured to theproximal end of staple driver member (350). The proximal end of staplinghead assembly driver (240) is secured to a drive bracket (250) via a pin(242). It should therefore be understood that staple driver member (350)will translate longitudinally relative to outer sheath (210) in responseto translation of stapling head assembly driver (240) and drive bracket(250) relative to outer sheath (210). Stapling head assembly driver(240) is configured to flex such that stapling head assembly driver(240) may follow along the preformed curve in shaft assembly (200) asstapling head assembly driver (240) is translated longitudinallyrelative to outer sheath (210). However, stapling head assembly driver(240) has sufficient column strength to transfer distal forces fromdrive bracket (250) to staple driver member (350). Details regarding themovement of drive bracket (250) will be described in greater detailbelow.

While not shown in FIG. 8 , it should be understood that shaft assembly(200) may further include one or more spacer elements within outersheath (210). Such spacer elements may be configured to support trocaractuation band assembly (230) and/or stapling head assembly driver (240)as trocar actuation band assembly (230) and/or stapling head assemblydriver (240) translate through outer sheath (210). For instance, suchspacer elements may prevent trocar actuation band assembly (230) and/orstapling head assembly driver (240) from buckling as trocar actuationband assembly (230) and/or stapling head assembly driver (240) translatethrough outer sheath (210). Various suitable forms that such spacerelements may take will be apparent to those of ordinary skill in the artin view of the teachings herein.

In addition to or in lieu of the foregoing, shaft assembly (200) may befurther constructed and operable in accordance with at least some of theteachings of U.S. Pat. Nos. 5,205,459; 5,271,544; 5,275,322; 5,285,945;5,292,053; 5,333,773; 5,350,104; 5,533,661; and/or 8,910,847, thedisclosures of which are incorporated by reference herein. Still othersuitable configurations will be apparent to one of ordinary skill in theart in view of the teachings herein.

D. Exemplary Actuator Handle Assembly

As shown in FIG. 9 , handle assembly (100) includes several componentsthat are operable to actuate anvil (400) and stapling head assembly(300). Handle assembly (100) also includes components that are operableto selectively lock out triggers (140, 150) based on the position ofanvil (400) relative to stapling head assembly (300). When triggers(140, 150) are locked out, firing trigger (150) is prevented frominitiating actuation of stapling head assembly (300). Thus, trigger(150) is only operable to initiate actuation of stapling head assembly(300) when the position of anvil (400) relative to stapling headassembly (300) is within a predefined range. The components of handleassembly (100) that provide the foregoing operability will be describedin greater detail below.

1. Exemplary Anvil Actuation Assembly

Knob (130) protrudes proximally from casing (110) of handle assembly andis rotatable relative to casing (110). As shown in FIG. 9 , a nut (160)is secured to the distal end of knob (130). In the present example, nut(160) is fixedly secured to the distal end of knob (130) such that nut(160) will rotate unitarily with knob (130). Nut (160) and knob (130)are configured to cooperate with trocar actuation rod (220) to therebytranslate trocar actuation rod (220) longitudinally relative to casing(110) in response to rotation of nut (160) and knob (130) relative tocasing (110). As noted above, trocar (330) will translate longitudinallyrelative to outer sheath (210) in response to translation of trocaractuation rod (220) relative to outer sheath (210) and casing (110).

The proximal portion of trocar actuation rod (220) is positioned withinhandle assembly (100) to engage nut (160) and knob (130). In particular,trocar actuation rod (220) is positioned within handle assembly (100)such that coarse helical threading (224) will selectively engage athread engagement feature (not shown) within the interior of nut (160);and such that fine helical threading (226) will selectively engage athread engagement feature (not shown) within the interior of knob (130).In some versions, the thread engagement feature of nut (160) comprisesan inwardly directed tab; while the thread engagement feature of knob(130) comprises a helical threading. Other suitable forms that suchthread engagement features may take will be apparent to those ofordinary skill in the art in view of the teachings herein.

In the present example, when nut (160) and knob (130) are rotatedrelative to casing (110), trocar actuation rod (220) travels proximallythrough a first range of longitudinal motion where coarse helicalthreading (224) is engaged with nut (160) to provide a relatively rapidrate of translation. Fine helical threading (226) is not engaged withknob (130) during this range of motion. When nut (160) and knob (130)are further rotated relative to casing (110) after trocar actuation rod(220) completes the first range of motion, trocar actuation rod (220)will continue to travel proximally through a second range oflongitudinal motion where fine helical threading (226) is engaged withknob (130) to provide a relatively slow rate of translation. Thus,trocar actuation rod (220) will translate proximally through a sequenceof rapid translation followed by slow translation, based on engagementbetween coarse helical threading (224) and nut (160) followed byengagement between fine helical threading (226) and knob (130).

It should be understood that when anvil (400) is coupled with trocar(330), rotation of knob (130) will provide corresponding translation ofanvil relative to stapling head assembly (300). It should also beunderstood that knob (130) may be rotated in a first angular direction(e.g., clockwise) to retract anvil (400) toward stapling head assembly(300); and in a second angular direction (e.g., counterclockwise) toadvance anvil (500) away from stapling head assembly (300). Knob (130)may thus be used to adjust the gap distance (d) between opposingsurfaces (412, 322) of anvil (400) and stapling head assembly (300)until a suitable gap distance (d) has been achieved as shown in FIG. 21Cand as described in greater detail below.

2. Exemplary Trigger Lockout Assembly

As noted above, knob may be used to adjust the gap distance (d) betweenopposing surfaces (412, 322) of anvil (400) and stapling head assembly(300). Setting an appropriate gap distance (d) before actuating staplinghead assembly (300) may be critical to the success of an anastomosis.For instance, if the gap distance (d) is too great, the staples that aredeployed at the anastomosis site may not be sufficiently formed bystaple forming pockets (414). This may result in leakage at theanastomosis site, and in some cases may ultimately lead to theseparation of the anatomical lumen sections that are joined at theanastomosis site. If the gap distance (d) is too small, the internalstructure of the tissue compressed between surfaces (412, 322) may bedamaged to the point where the structural integrity of the tissue iscompromised. This may prevent the tissue from adequately holding theformed staples, which again may result in leakage or other failure ofthe anastomosis. It may therefore be desirable to provide the operatorwith some form of feedback indicating whether the gap distance (d) iswithin an appropriate range. It may also be desirable to prevent theoperator from actuating stapling head assembly (300) unless the gapdistance (d) is within an appropriate range.

FIGS. 9-12E show components that provide feedback to the operator toindicate whether the gap distance (d) is within an appropriate range;and prevent the operator from actuating stapling head assembly (300)unless the gap distance (d) is within an appropriate range. As best seenin FIGS. 12B-12C, a bracket (500) is configured and positioned to movein response to movement of trocar actuation rod (220). As best seen inFIG. 10 , bracket (500) includes a rigid body (502) that defines a firstslot (504), a second slot (506), and a third slot (508). An uprightfeature (510) is positioned at the proximal end of body (502) anddefines an opening (512). Trocar actuation rod (220) extends coaxiallythrough opening (512). As shown in FIG. 9 , a coil spring (170) isinterposed between the proximal end of upright feature (510) and a rigidbulkhead feature that is defined by casing (110) and that forms asupport journal for nut (160). The bulkhead is fixed within casing (110)and thereby provides a ground for the proximal end of coil spring (170),such that coil spring (170) resiliently imparts a distal bias to bracket(500) via upright feature (510). Bracket (500) further includes alaterally presented flange (516) at the distal end of body (502). Flange(516) defines a slot (514).

As best seen in FIGS. 12B-12C, an indicator member (520) is configuredto pivot in response to translation of bracket (500). As best seen inFIG. 11 , indicator member (520) comprises an upright arm (522), a snappin (524) projecting laterally from a lower end of arm (522), anindicator needle (526) projecting laterally from an upper end of arm(522), and a coupling pin (528) projecting laterally from anintermediate region of arm (522). Snap pin (524) is configured to snapinto a complementary recess provided by casing (110). Snap pin (524)thereby secures indicator member (520) to casing (110) yet permitsindicator member (520) to pivot relative to casing (110) about thelongitudinal axis of snap pin (524). Indicator needle (526) ispositioned to be visible through window (114) of handle assembly (110)to thereby visually indicate the pivotal position of indicator member(520). Coupling pin (528) is slidably received in slot (514) of flange(516) of bracket (500). This engagement between indicator member (520),casing (110), and bracket (500) provides pivotal movement of indicatormember (520) in response to translation of bracket (500).

Bracket (500) is configured to selectively prevent and permit actuationof triggers (140, 150). In particular, slots (504, 506) of bracket (500)are configured to selectively provide clearance for actuation oftriggers (140, 150). As shown in FIGS. 12A-12E, safety trigger (140) ispivotably coupled with a first upright member (144). First uprightmember (144) is coupled with casing (110) such that first upright member(144) is configured to translate upwardly in response to pivoting ofsafety trigger (140) toward pistol grip (112). However, body (502) ofbracket (500) is configured to prevent this movement of first uprightmember (144) and safety trigger (140) by engaging the upper end (146) offirst upright member (144). Body (502) thus blocks movement of firstupright member (144) and safety trigger (140) until bracket (500) ismoved to a position where slot (506) is aligned with upper end (146) tothereby provide clearance for upward movement of first upright member(144). It should therefore be understood that safety trigger (140)cannot be pivoted toward pistol grip (112) until slot (506) ispositioned over upper end (146).

Similarly, firing trigger (150) is pivotably coupled with a secondupright member (154). Second upright member (154) is coupled with casing(110) such that second upright member (154) is configured to translateupwardly in response to pivoting of safety trigger (150) toward pistolgrip (112). However, body (502) of bracket (500) is configured toprevent this movement of second upright member (154) and firing trigger(150) by engaging the upper end (156) of second upright member (154).Even if safety trigger (140) is pivoted out of the way to otherwisepermit movement of firing trigger (150), body (502) blocks movement ofsecond upright member (154) and firing trigger (150) until bracket (500)is moved to a position where slot (504) is aligned with upper end (156)to thereby provide clearance for upward movement of second uprightmember (154). It should therefore be understood that, even if safetytrigger (140) is pivoted out of the way to otherwise permit movement offiring trigger (150), firing trigger (150) cannot be pivoted towardpistol grip (112) until slot (504) is positioned over upper end (156).

Third slot (508) is configured to receive a downwardly projecting boss(223) of clip (222), which is rigidly secured to trocar actuation rod(220). While casing (110) is configured to allow bracket (500) totranslate longitudinally within casing (110), casing (110) includesrails, channels, and/or other features that prevent bracket (500) fromrotating within casing (110). Thus, the positioning of boss (223) inslot (508) prevents clip (222) and trocar actuation rod (220) fromrotating within casing (110). Boss (223) and slot (508) neverthelessallow bracket (500) to translate longitudinally within casing (110) aswill be described in greater detail below.

FIGS. 12A-12E depict the above-described components at various stages ofoperation. In particular, in FIG. 12A, trocar actuation rod (220) is ina distal-most position, such that trocar (330) is in a distal-mostposition. At this stage, the operator may couple anvil (400) with trocar(330) by inserting trocar (330) into bore (422) until latch members(430) are secured to head (334) of trocar (330). The operator thenrotates knob (130), which rotates nut (160). As knob (130) and nut (160)rotate, engagement between coarse helical threading (224) of trocaractuation rod (220) and the complementary feature of nut (160) causestrocar actuation rod (220) to retract proximally at a relatively rapidrate, such that trocar actuation rod (220) reaches the position shown inFIG. 12B. This provides proximal retraction of trocar actuation rod(220) provides retraction of trocar (330) and anvil (400). As trocaractuation rod (220) moves from the position shown in FIG. 12A to theposition shown in FIG. 12B, bracket (500) remains stationary. This isdue to the fact that clip (222) is spaced apart from upright feature(510) at the stage shown in FIG. 12A and does not engage upright feature(510) until trocar actuation rod (220) reaches the position shown inFIG. 12B.

After reaching the stage shown in FIG. 12B, the operator may continuerotating knob (130) and nut (160), which causes further proximalretraction of trocar actuation rod (220) as shown in FIG. 12C. This ofcourse causes further proximal retraction of trocar (330) and anvil(400). As trocar actuation rod (220) moves from the position shown inFIG. 12B to the position shown in FIG. 12C, clip (222) bears againstbracket (500), driving bracket (500) proximally. This proximal movementof bracket (500) causes indicator member (520) to pivot from theposition shown in FIG. 12B to the position shown in FIG. 12C due to thepositioning of pin (528) in slot (514) of flange (516).

As indicator member (520) pivots from the position shown in FIG. 12B tothe position shown in FIG. 12C, the operator may observe the position ofindicator needle (526) through window (114) of handle assembly (110). Asnoted above, a series of hash marks, colored regions, and/or other fixedindicators may be positioned adjacent to window (114) in order toprovide a visual context for indicator needle (526), therebyfacilitating operator evaluation of the position of needle (526) withinwindow (114). It should be understood that the position of needle (526)within window (114) will be indicative of the longitudinal position oftrocar (330) and anvil (400). The position of needle (526) within window(114) will thus indicate the gap distance (d) between opposing surfaces(412, 322) of anvil (400) and stapling head assembly (300). Whileobserving the position of needle (526) within window (114), the operatormay rotate knob (130) clockwise or counterclockwise to further retractor advance trocar (330) and anvil (400), thereby providing fineadjustment of the gap distance (d) until a desired gap distance (d) isreached within an appropriate range.

In order to provide fine control of the gap distance (d) adjustment atthe stage shown in FIG. 12C, trocar actuation rod (220) will be at alongitudinal position where fine helical threading (226) is engaged witha complementary feature of knob (130) and coarse helical threading (224)is disengaged from the complementary feature of nut (160). In someversions, coarse helical threading (224) disengages nut (160) and finehelical threading (226) begins to engage knob (130) once trocaractuation rod (220) reaches the longitudinal position shown in FIG. 12B(i.e., when clip (222) first engages upright member (510)). In someother versions, the transition from engagement by coarse helicalthreading (224) to fine helical threading (226) occurs sometime betweenthe stage shown in FIG. 12B and the stage shown in FIG. 12C. Othersuitable stages at which the coarse-to-fine transition may occur will beapparent to those of ordinary skill in the art in view of the teachingsherein. It should also be understood that some alternative versions oftrocar actuation rod (220) may have just a single threading section,with the pitch of the threading being consistent along the length of thethreading. In other words, trocar actuation rod (220) does notnecessarily need to have two different sections of threading (224, 226)with different pitches.

At the stage shown in FIG. 12C, slot (506) is aligned with upper end(146) to thereby provide clearance for upward movement of first uprightmember (144). Similarly, slot (504) is aligned with upper end (156) tothereby provide clearance for upward movement of second upright member(154). In the present example, slots (504, 506) are sized and positionedsuch that slots (504, 506) only provide clearance for upward movement ofupright members (144, 154) when the gap distance (d) is within aclinically acceptable range. By way of example only, a “clinicallyacceptable range” for the gap distance (d) may be between approximately0.110 inches and approximately 0.040 inches. As another merelyillustrative example, a “clinically acceptable range” for the gapdistance (d) may be between approximately 0.110 inches and approximately0.020 inches. Even when slots (504, 506) are positioned to provideclearance for upward movement of upright members (144, 154) as shown inFIG. 12C, safety trigger (140) will still block pivotal movement offiring trigger (150) about a pin (152) (FIG. 9 ) when safety trigger(140) is in the non-actuated position shown in FIG. 12C. Thus, in orderto enable movement of firing trigger (150), the operator will need tofirst actuate safety trigger (140) about a pin (142) (FIG. 9 ) from theposition shown in FIG. 12C to the position shown in FIG. 12D.

As shown in FIG. 12D, upper end (146) passes through slot (506) assafety trigger (140) is pivoted from the position shown in FIG. 12C tothe position shown in FIG. 12D. It should be understood that thismovement of upper end (146) would not be possible at the stages shown inFIGS. 12A-12B (when the gap distance (d) is too great) because body(502) would physically block upward movement of upright member (144),thereby physically blocking pivotal movement of safety trigger (140). Inthe present example, a cap (not shown) incorporated into knob (130)prevents knob (130) from rotating to a point where anvil (400) would beretracted too far proximally (such that the gap distance (d) is toosmall). In some other variations, even if knob (130) were to permitanvil (400) to be retracted too far proximally (such that the gapdistance (d) is too small), body (502) would physically block upwardmovement of upright member (144), thereby physically blocking pivotalmovement of safety trigger (140), in the event that the operatorretracts trocar (330) and anvil (400) too far proximally (such that thegap distance (d) is too small). Regardless of whether body (502), knob(130), or some other feature prevents actuation when the gap distance(d) would be too small, it should be understood that instrument (10)permits actuation of safety trigger (140) only when the gap distance (d)is within the clinically acceptable range.

As noted above, safety trigger (140) is configured to prevent actuationof firing trigger (150) until safety trigger (140) has been actuated.Once safety trigger (140) has been actuated, the operator may actuatefiring trigger (150) from the position shown in FIG. 12D to the positionshown in FIG. 12E. As shown in FIG. 12E, upper end (156) passes throughslot (504) as firing trigger (150) is pivoted from the position shown inFIG. 12D to the position shown in FIG. 12E. It should be understoodthat, even in the complete absence of safety trigger (140), thismovement of upper end (156) would not be possible at the stages shown inFIGS. 12A-12B (when the gap distance (d) is too great) because body(502) would physically block upward movement of upright member (154),thereby physically blocking pivotal movement of firing trigger (150). Itshould also be understood that body (502) would also physically blockupward movement of upright member (154), thereby physically blockingpivotal movement of firing trigger (150), in the event that the operatorretracts trocar (330) and anvil (400) too far proximally (such that thegap distance (d) is too small). Thus, even in the complete absence ofsafety trigger (140), firing trigger (150) may only be actuated when thegap distance (d) is within the clinically acceptable range.

Firing trigger (150) of the present example includes an integralactuation paddle (158). Paddle (158) pivots forwardly as firing trigger(150) pivots from the position shown in FIG. 12D to the position shownin FIG. 12E. Paddle (158) is configured to actuate a switch of a motoractivation module (180), which is shown in FIG. 9 , when firing trigger(150) pivots from the position shown in FIG. 12D to the position shownin FIG. 12E. Motor activation module (180) is in communication withbattery pack (120) and motor (160), such that motor activation module(180) is configured to provide activation of motor (160) with electricalpower from battery pack (120) in response to paddle (158) actuating theswitch of motor activation module (180). Thus, motor (160) will beactivated when firing trigger (150) is pivoted from the position shownin FIG. 12D to the position shown in FIG. 12E. This activation of motor(160) will actuate stapling head assembly (300) as described in greaterdetail below.

3. Exemplary Stapling Head Actuation Assembly

FIGS. 13-20D show various components that are operable to actuatestapling head assembly (300). These components include motor (160), agearbox (162), a rotary cam member (700), a cam follower (600), drivebracket (250) and stapling head assembly driver (240). Gearbox (162) iscoupled with a drive shaft of motor (160) and is further coupled withcam member (700). Activation of motor (160) thus causes rotation of cammember (700) via gearbox (162). Various suitable configurations that maybe used for gearbox (162) will be apparent to those of ordinary skill inthe art in view of the teachings herein. Cam member (700) is configuredto interact with cam follower (160) to pivot cam follower (160) in twoangular directions about a pin (118) as will be described in greaterdetail below. Pin (118) is coupled with casing (110). A bushing (701)provides rotary support to cam member (700) relative to casing (110).

Cam follower (600) is pivotably coupled with drive bracket (250) via apair of integral pins (602), which are received in complementary notches(252) of drive bracket (250). As shown in FIGS. 14-15 , cam follower(600) includes a first bearing feature (604) and a second bearingfeature (610). First bearing feature (604) consists of a rounded,horizontally extending surface. Second bearing feature (610) is shapedlike a quarter-pie defined by a straight vertical surface (612), ahorizontally extending surface (614), and a curved surface (616). Secondbearing feature (610) projects proximally relative to first bearingfeature (504).

FIGS. 16-17 show cam member (700) in greater detail. Cam member (700)comprises a distal face (702), a distally projecting post (704), and anouter circumferential surface (706). A first cam feature (710) and asecond cam feature (720) project distally from distal face (702). Post(704) engages bushing (701). First cam feature (710) comprises a firstsurface region (712), a second surface region (714), and a third surfaceregion (716). First surface region (712) is convexly defined by arelatively large radius of curvature, such that first surface region(712) is nearly flat. Second surface region (714) is convexly defined bya progressively increasing radius of curvature. Third surface region(716) is concavely defined by a relatively large radius of curvature. Inaddition to projecting distally from distal face (702), second camfeature (720) projects outwardly from outer circumferential surface(706). Second cam feature (720) includes a first surface region (722)and a second surface region (724). First surface region (722) issubstantially flat while second surface region (724) is concavelycurved. The origin of the radius of curvature for each curved surfaceregion (712, 714, 716, 724) is offset from the center of post (704).

FIGS. 18A-18B show the general interaction between cam follower (600)and first and second cam features (710, 720), though this interactionwill be described in greater detail below with reference to FIGS.20A-20D. As cam member (700) is rotated from the position shown in FIG.18A to the position shown in FIG. 18B, first cam feature (710) bearsagainst first bearing feature (604) of cam follower (600), causing camfollower to pivot about pin (118). In the view shown in FIGS. 18A-18B,cam follower (600) pivots counterclockwise as cam member (700) isrotated from the position shown in FIG. 18A to the position shown inFIG. 18B. As can be seen in the transition from FIG. 18A to FIG. 18B,this counterclockwise pivoting of cam follower (600) drives drivebracket (250) and stapling head assembly driver (240) distally, therebyactuating stapling head assembly (300). As cam member (700) continues torotate in the same direction back toward the position shown in FIG. 18A,second cam feature (720) engages and bears against second bearingfeature (610) of cam follower (600), causing cam follower (600) to pivotclockwise about pin (118). This clockwise pivoting of cam follower (600)about pin (118) retracts drive bracket (250) and stapling head assemblydriver (240) proximally back toward the position shown in FIG. 18A.

Referring back to FIGS. 16-17 , a third cam feature (730) projectsoutwardly from outer circumferential surface (706). Third cam feature(730) comprises a first surface region (732) and a second surface region(734). First surface region (732) is flat and is oriented generallytangentially relative to outer circumferential surface (706). Secondsurface region (732) is also flat and is oriented radially outwardlyrelative to outer circumferential surface (706). Third cam feature (730)is configured to interact with a rocker member (800) as shown in FIGS.19A-19B. Rocker member (800) comprises an integral pin (802), a bearingmember (804), and a paddle (806). Pin (802) is pivotably coupled withcasing (110), such that rocker member (800) is pivotable within casing(110) about the longitudinal axis defined by pin (802). Bearing member(804) is configured to interact with third cam feature (730) as will bedescribed in greater detail below. Paddle (806) is configured to actuatea pair of switch buttons (192) of a motor stop module (190) as will alsobe described in greater detail below.

FIG. 19A shows cam member (700) in the same position as shown in FIG.18A. At this stage, second surface region (734) of third cam feature(730) is adjacent to bearing member (804) of rocker member (800). FIG.19B shows cam member (700) in a position where cam member (700) has beenrotated past the position shown in FIG. 18B and back toward the positionshown in FIG. 18A. However, cam member (700) has not completed a fullrevolution. At the stage shown in FIG. 19B, first surface region (732)has engaged and borne against bearing member (804), thereby pivotingrocker member (800) about the longitudinal axis defined by pin (802).This has caused paddle (806) to actuate switch buttons (192) of motorstop module (190). Motor stop module (190) is configured to preventmotor (160) from further activation when switch buttons (192) have beenactuated. In some versions, motor stop module (190) creates a shortcircuit when switch buttons (192) are actuated, thereby stopping furtheractivation of motor (160). Also in some versions, motor stop module(190) couples battery pack (120) with a power sink, in addition to shortcircuiting motor (160), when switch buttons (192) are actuated. This mayresult in discharge of battery pack (120) in addition to stoppingactivation of motor (160) once an actuation stroke of stapling headassembly (300) has been completed. By way of example only, motor stopmodule (190) may be configured and operable in accordance with at leastsome of the teachings of U.S. Pub. No. 2015/0083774, issued as U.S. Pat.No. 9,907,552 on Mar. 6, 2018, the disclosure of which is incorporatedby reference herein. Other suitable configurations will be apparent tothose of ordinary skill in the art in view of the teachings herein.

FIGS. 20A-20D schematically depict the interaction between cam member(700), features of cam follower (600), and features of rocker member(800) as cam member (700) rotates. It should be understood that therotation of cam member (700) throughout the stages shown in FIGS.20A-20D is driven by motor (160) and gearbox (162). FIG. 20A shows cammember (700) in the same position as shown in FIGS. 18A and 19A. At thisstage, first bearing feature (604) of cam follower (600) is positionedon first surface region (712) and bearing member (804) or rocker member(800) is adjacent to second surface region (734) of third cam feature(730). Also at this stage, knife member (340) and staple driver member(350) are in proximal positions, such that stapling head assembly (300)is in a non-actuated state. As cam member (700) is rotated to theposition shown in FIG. 20B, second surface region (714) bears againstbearing member (610), thereby driving bearing member (610) upwardly.This causes cam follower (600) to pivot about pin (118) to the positionshown in FIG. 18B. Cam follower (600) thus drives knife member (340) andstaple driver member (350) distally via drive bracket (250) and staplinghead assembly driver (240). Stapling head assembly (300) is thus in anactuated state at the stage shown in FIG. 20B. In some versions, cammember (700) rotates through an angular range of approximately 270° inorder to transition stapling head assembly (300) from the non-actuatedstate to the actuated state.

After stapling head assembly (300) has been actuated, cam member (700)continues to rotate to the position shown in FIG. 20C. At this stage,first surface region (722) of second cam member (720) begins to engagecurved surface (616) of second bearing feature (610) of cam follower(600). As cam member (700) continues to rotate to the position shown inFIG. 20D, second surface region (724) engages curved surface (616) ofsecond bearing feature (610), driving second bearing feature (610)downwardly. This causes cam follower (600) to pivot about pin (118) backfrom the position shown in FIG. 18B toward the position shown in FIG.18A. Cam follower (600) thus drives knife member (340) and staple drivermember (350) proximally via drive bracket (250) and stapling headassembly driver (240). In addition, first surface region (732) hasengaged and borne against bearing member (804), thereby pivoting rockermember (800) about the longitudinal axis defined by pin (802) at thestage shown in FIG. 20D. Rocker member (800) is thus in the same statein FIG. 20D as shown in FIG. 19B. Motor stop module (190) has thus beenactuated at the stage shown in FIG. 20D.

It should be understood from the foregoing that cam member (700) isoperable to drive knife member (340) and staple driver member (350)distally, then drive knife member (340) and staple driver member (350)proximally and actuate motor stop module (190) by rotating in a singleangular direction through the range of motion shown in FIGS. 20A-20D.Other suitable ways in which knife member (340), staple driver member(350), and motor stop module (190) may be actuated will be apparent tothose of ordinary skill in the art in view of the teachings herein.

E. Exemplary Anastomosis Procedure

FIGS. 21A-21E show instrument (10) being used to form an anastomosis(70) between two tubular anatomical structures (20, 40). By way ofexample only, the tubular anatomical structures (20, 40) may comprisesections of a patient's esophagus, sections of a patient's colon, othersections of the patient's digestive tract, or any other tubularanatomical structures. As shown in FIG. 21A, anvil (400) is positionedin one tubular anatomical structure (20) and stapling head assembly(300) is positioned in another tubular anatomical structure (40). Inversions where tubular anatomical structures (20, 40) comprise sectionsof a patient's colon, stapling head assembly (300) may be inserted viathe patient's rectum. It should also be understood that the proceduredepicted in FIGS. 21A-21E is an open surgical procedure, though theprocedure may instead be performed laparoscopically. Various suitableways in which instrument (10) may be used to form an anastomosis (70) ina laparoscopic procedure will be apparent to those of ordinary skill inthe art in view of the teachings herein.

As shown in FIG. 21A, anvil (400) is positioned in tubular anatomicalstructure (20) such that shank (420) protrudes from the open severed end(22) of tubular anatomical structure (20). A purse-string suture (30) isprovided about a mid-region of shank (420) to generally secure theposition of anvil (400) in tubular anatomical structure (20). Similarly,stapling head assembly (300) is positioned in tubular anatomicalstructure (40) such that trocar (330) protrudes from the open severedend (42) of tubular anatomical structure (20). A purse-string suture(50) is provided about a mid-region of shaft (332) to generally securethe position of stapling head assembly (300) in tubular anatomicalstructure (40).

Next, anvil (400) is secured to trocar (330) by inserting trocar (330)into bore (422) as shown in FIG. 21B. Latch members (430) engage head(334) of trocar (330), thereby providing a secure fit between anvil(400) and trocar (330). The operator then rotates knob (130) whileholding casing (110) stationary via pistol grip (112). This rotation ofknob (130) causes trocar (330) and anvil (400) to retract proximally (asdescribed above with reference to FIGS. 12A-12C). As shown in FIG. 21C,this proximal retraction of trocar (330) and anvil (400) compresses thetissue of tubular anatomical structures (20, 40) between surfaces (412,322) of anvil (400) and stapling head assembly (300). The operatorobserves the position of needle (526) within window (114) to determinewhether the gap distance (d) between opposing surfaces (412, 322) ofanvil (400) and stapling head assembly (300) is appropriate; and makesany necessary adjustments via knob (130).

Once the operator has appropriately set the gap distance (d) via knob(130), the operator actuates safety trigger (140) (as shown in FIG. 12D)to enable actuation of firing trigger (150). The operator then actuatesfiring trigger (150) (as shown in FIG. 12D). This causes paddle (158) toactuate the switch of a motor activation module (180), therebyactivating motor to rotate cam member (700) (as shown in FIGS. 20A-20D).This rotation of cam member (700) actuates stapling head assembly (300)by driving knife member (340) and staple driver member (350) distally asshown in FIG. 21D. As knife member (340) translates distally, cuttingedge (342) of knife member (340) cooperates with inner edge (416) ofanvil (400), thereby shearing excess tissue that is positioned withinannular recess (418) of anvil (400) and the interior of knife member(340).

As shown in FIG. 4 , anvil (400) of the present example includes abreakable washer (417) within annular recess (418). This washer (417) isbroken by knife member (340) when the knife member (340) completes afull distal range of motion from the position shown in FIG. 21C to theposition shown in FIG. 21D. The progressively increasing radius ofcurvature of second surface region may provide an increasing mechanicaladvantage as knife member (340) reaches the end of its distal movement,thereby providing greater force by which to break the washer (417). Ofcourse, the breakable washer (417) may be omitted entirely in someversions. In versions where washer (417) is included, it should beunderstood that washer (417) may also serve as a cutting board for knifemember (340) to assist in cutting of tissue. Such a cutting techniquemay be employed in addition to or in lieu of the above-noted shearingaction between inner edge (416) and knife member (340).

As staple driver member (350) translates distally from the positionshown in FIG. 21C to the position shown in FIG. 21D, staple drivermember (350) drives staples (90) through the tissue of tubularanatomical structures (20, 40) and into staple forming pockets (414) ofanvil (400). Staple forming pockets (414) deform the driven staples (90)into a “B” shape as is known in the art. The formed staples (90) thussecure the ends of tissue together.

After the operator has actuated stapling head assembly (300) as shown inFIG. 21D, the operator rotates knob (130) to drive anvil (400) distallyaway from stapling head assembly (300), increasing the gap distance (d)to facilitate release of the tissue between surfaces (412, 322). Theoperator then removes instrument (10) from the patient, with anvil (400)still secured to trocar (330). Referring back to the example where thetubular anatomical structures (20, 40) comprise sections of a patient'scolon, instrument (10) may be removed via the patient's rectum. Withinstrument (10) is removed, the tubular anatomical structures (20, 40)are left secured together by two annular arrays of staples (90) at ananastomosis (70) as shown in FIG. 21E. The inner diameter of theanastomosis (70) is defined by the severed edge (60) left by knifemember (340).

II. Exemplary Methods for Resetting Instrument for Subsequent Firings

In some instances, it may be desirable to enable resetting of instrument(10) after firing. For example, it may be desirable to fire a singleinstrument (10) multiple times in a testing or quality control setting.As another merely illustrative example, it may be desirable to fire asingle instrument (10) multiple times to demonstrate operation ofinstrument (10) in the context of a training exercise. In othersituations, after instrument (10) has been used in a procedure, it maybe desirable to reset instrument (10) before, during, or afterinstrument (10) is cleaned, sterilized, and/or otherwise reprocessed forsubsequent re-use. The following examples provide techniques by which analready fired instrument (10) may be re-set for subsequent firing.

A. Exemplary Powered Reset of Manual Instrument Through Reversed MotorRotation

FIG. 22 shows a pistol grip (2212) of an exemplary alternativeinstrument (2010), with a portion of the casing removed to show internalcomponents. Instrument (2010) is configured to operate substantiallysimilarly to instrument (10). Therefore, identical or substantiallysimilar components are marked with the same reference numerals, withoutfurther discussion. It should be understood that any components andoperabilities of instrument (2010) that are not described explicitlybelow may be the same as the components and operabilities of instrument(10) described above. Instrument (2010) includes a motor (2160) may beactivated like motor (160) described above, such as by actuation of afiring trigger (not shown) that is configured to operate substantiallysimilarly to firing trigger (150) of instrument (10). Moreover,instrument (2010) of the present example includes a safety trigger thatis configured and operable like safety trigger (140) discussed above.Instrument (2010) also includes other features of the trigger lockoutassembly discussed above and shown best in FIGS. 9-12E.

Instrument (2010) is different than instrument (10) in that instrument(2010) includes a switch (2164) that is in communication with motor(2160). Switch (2164) is operable to reverse the polarity of motor(2160) when switch (2164) is actuated. Thus, it will be understood thatactuating switch (2164) changes the direction of rotation of motor(2160), gear box (2162), cam (700), and bushing (701), when motor (2160)is activated by actuation of a firing trigger, such as firing trigger(140) discussed above. Moreover, in order to allow for re-activation ofmotor (2160) after an actuation stroke of stapling head assembly (300)has been completed, instrument (2010) in some examples does not includea motor stop module, power sink, etc., or other features that preventsubsequent activation of motor (2160) once an actuation stroke ofstapling head assembly (300) has been completed. In other examples,instrument (2010) may include such features that prevent re-activationof motor (2160), but such features may be configured to be disabled(i.e., such that they cannot prevent re-activation of motor (2160)).

In the present example, switch (2164) is located at the bottom of pistolgrip (2212). In some versions, switch (2164) is exposed such that switch(2164) is accessible without having to disassemble instrument (2010). Insome other versions, switch (2164) is positioned within pistol grip(2212) or elsewhere within instrument (2010) such that at least aportion of instrument (2010) must be disassembled in order to accessswitch (2164). As yet another merely illustrative example, switch (2164)may be recessed within pistol grip (2212) such that switch (2164) may beaccessed with a tool inserted through a small opening in pistol grip(2212); yet such that switch (2164) is not conspicuous or easilyaccessible to the casual operator of instrument (2010). Other suitableways in which switch (2164) may be positioned and accessible will beapparent to those of ordinary skill in the art in view of the teachingsherein. Similarly, various suitable forms that switch (2164) may takewill be apparent to those of ordinary skill in the art in view of theteachings herein.

FIG. 23 shows a first example of a method of resetting instrument (10,2010) after firing, such as after an actuation stroke of stapling headassembly (300) of instrument (10, 2010). As shown, the method includesthe step of reversing the polarity of motor (160, 2160) (block 2200). Insome versions, reversing the polarity includes actuating switch (2164)of instrument (2010), thus reversing the polarity of motor (2160) asdiscussed above. Other suitable ways in which the polarity of motor(160, 2160) may be reversed will be apparent to those of ordinary skillin the art in view of the teachings herein. The method further includesthe step of disengaging trigger lockout assembly (block 2202) asdiscussed above (e.g., by actuating safety trigger (140)) to allow forfiring of trigger (150) and thus activation of motor (160, 2160). Oncethe trigger lockout assembly is disengaged, the operator may actuatefiring trigger (140) to activate motor (160, 2160) (block 2204). Sincethe polarity of motor (160, 2160) is reversed at this stage, it shouldbe understood that motor (160, 2160) and the associated drive componentswill move in a direction that is opposite to the direction of motiondescribed above in the context of firing stapling head assembly (300).

FIGS. 25A-25D schematically depict the interaction between cam member(700), features of cam follower (600), and features of rocker member(800) as cam member (700) rotates in response to activation of motor(160, 2160) (block 2204) when the polarity of motor (160, 2160) isreversed. It should be understood that the rotation of cam member (700)throughout the stages shown in FIGS. 25A-25D is driven by motor (160)and gearbox (162). It should be further understood that the interactionbetween cam member (700), cam follower (600), and features of rockermember (800) occurs essentially in the opposite manner as shown in FIGS.20A-20D and as described above. Particularly, cam (700) in FIG. 25A isin the same position relative to cam follower (600) and rocker member(800) shown in FIG. 20D; in FIG. 25B is in the same position relative tocam follower (600) and rocker member (800) as shown in FIG. 20C; in FIG.25C is in the same position relative to cam follower (600) and rockermember (800) as shown in FIG. 20B; and in FIG. 25D is in the sameposition relative to cam follower (600) and rocker member (800) as shownin FIG. 20A. Of course, as noted above, in the present example,actuation of rocker member (800) does not result in the activation of amotor stop module and/or other features that prevent subsequent uses ofinstrument (10, 2010). Due to the reversed polarity of motor (160,2160), activation of motor (160, 2160) causes rotation of cam (700) inan opposite rotational direction that occurred during the prioractivation of motor (160, 2160) (e.g., FIGS. 20A-20D) to thereby rotatecam (700) from the position shown in FIG. 25A to the position shown inFIG. 25D.

As motor (160, 2160) is activated at a reversed polarity, cam (700)rotates from the position shown in FIG. 25A to the position in FIG. 25B.Third surface region (716) of first cam feature (710) bears againstsecond bearing feature (610) of cam follower (600), driving secondbearing feature (610) upwardly. This causes cam follower (600) to pivotabout pin (118) from the position shown in FIG. 18A toward the positionshown in FIG. 18B. As cam member (700) is rotated further to theposition shown in FIG. 25C, second surface region (714) bears againstbearing member (610), such that cam follower (60)) reaches the positionshown in FIG. 18B. Cam follower (600) thus drives knife member (340) andstaple driver member (350) distally via drive bracket (250) and staplinghead assembly driver (240), transitioning stapling head assembly (300)back to the actuated position at the stage shown in FIG. 25C.

As cam (700) rotates further, first bearing feature (604) of camfollower (600) eventually reaches first surface region (712) of cam(700). Second surface region (724) of second cam feature (720) engagessecond bearing feature (610) of cam follower (600). This causes camfollower (600) to pivot about pin (118) back from the position shown inFIG. 18B toward the position shown in FIG. 18A. Cam follower (600) thusdrives knife member (340) and staple driver member (350) proximally viadrive bracket (250) and stapling head assembly driver (240). Therefore,first bearing feature (604) of cam follower (600) is again positioned onfirst surface region (712) and bearing member (610) or rocker member(800) is adjacent to second surface region (734) of third cam feature(730). Also at this stage, knife member (340) and staple driver member(350) are in proximal positions, such that stapling head assembly (300)is returned to a non-actuated state. In some versions, a resilientmember (e.g., a coil spring engaged with linearly translating componentsof the drive assembly such as stapling head assembly driver (240) and/ordrive bracket (250); and/or a torsion spring engaged with cam follower(600); etc.) provides a bias to assist in returning cam follower (600)from the position shown in FIG. 25C and FIG. 18B to the position shownin FIG. 25D and FIG. 18A.

It should be understood from the foregoing that rotating cam (700) in anopposite manner of that shown in FIGS. 20A-20D, as shown in FIGS. 25A-D,results in resetting of instrument (10, 2010). With instrument (10,2010) reset in this fashion, stapling head assembly (300) is in anon-actuated state; and cam (700) and cam follower (600) are in apre-firing state. Returning back to FIG. 24 , at this stage the operatormay then reload stapling head assembly (300) with staples (90) (block2206), and reengage the trigger lockout assembly (block 2208) to preventundesired firing of instrument (10, 2010) until instrument (10, 2010) isin a state and position where it is ready to be intentionally fired.

B. Exemplary Manual Reset of Instrument

In addition to or in lieu of the method described above, an operator mayreset instrument (10, 2010) for subsequent firings without activatingmotor (160, 2160) at all. For instance, FIG. 24 shows another exemplarymethod of resetting instrument (10, 2010). In this example, the operatormay remove battery pack (e.g., battery pack (120)) (block 2210) andremove at least a portion of casing (110) to expose certain internalcomponents of instrument (10, 2010), such as cam (700) (block 2212).Once cam (700) is exposed, the operator may manually rotate cam (700)from the position shown in FIG. 25A (which may be referred to herein asthe “fired position”) to the position shown in FIG. 25D (which may bereferred to herein as the “home position”) (block 2214). The user maymanually rotate cam (700) by hand or by some sort of tool or device,such as a wrench, screwdriver, or other tool that is configured toprovide a rotational force on cam (700). Moreover, cam (700) may includefeatures to enable the use of such tools or devices. Various suitableforms that such features and tools may take will be apparent to those ofordinary skill in the art in view of the teachings herein.

It will be understood that when cam (700) is manually rotated inreverse, the interaction between cam (700), cam follower (600), androcker member (800), as well as stapling head assembly (300), will besubstantially identical to the interaction between cam (700) and suchcomponents with motor-driven reversed rotation of cam (700) as describedwith respect to FIG. 23 . Manually rotating cam (700) in an oppositemanner of that shown in FIGS. 20A-20D, thus provides the movement shownin FIGS. 25A-25D, resulting in resetting of instrument (10, 2010) asdescribed above. It will be further understood that the operator mustsubject cam (700) to a sufficient level of rotational force thatovercomes the resistance from other components such as cam follower(600), rocker member (800), and stapling head assembly (300), etc.), inorder to rotate cam (700) in reverse. Once cam (700) has been manuallyrotated to the position shown in FIG. 25D, the operator then replacescasing (110) (block 2216), reloads stapling head assembly (300) withstaples (90) (block 2218), and reengages the trigger lockout assembly(block 2219) to prevent undesired firing of instrument (10, 2010) untilinstrument (10, 2010) is in a state and position where it is ready to beintentionally fired.

FIG. 26 shows another exemplary method of resetting instrument (10,2010) for subsequent firings without activating motor (160, 2160). Themethod shown in FIG. 26 may be performed in addition to or in lieu ofother methods for resetting instrument (10, 2010). As shown, theoperator removes battery pack (120) (block 2220) and removes at least aportion of casing (110) (block 2222) to expose certain internalcomponents of instrument (10, 2010), such as cam (700). Once cam (700)is exposed, the operator displaces or removes cam follower (600) (block2224) such that cam (700) may be more easily moved from the positionshown in FIGS. 20D and 25A to the position shown in FIGS. 20A and 25D(block 2226) without substantially interacting with cam follower (600),stapling head assembly (300), and other components. The operator maymanually rotate cam (700) by hand or by some sort of tool or device,such as a wrench, screwdriver, or other tool that is configured toprovide a rotational force on cam (700). Moreover, cam (700) may includefeatures to enable the use of such tools or devices.

Once cam (700) has been manually rotated from the fired position back tothe home position, the operator may replace cam follower (600) (block2227) such that cam follower (600) is re-engaged with cam (700). Theoperator then replaces casing (110) (block 2228), reloads stapling headassembly (300) with staples (90) (block 2230), and reengages the triggerlockout assembly (block 2231) to prevent undesired firing of instrument(10, 2010) until instrument (10, 2010) is in a state and position whereit is ready to be intentionally fired.

FIG. 27 shows another exemplary method of resetting instrument (10,2010) for subsequent firings without activating motor (160, 2160). Themethod shown in FIG. 26 may be performed in addition to or in lieu ofother methods for resetting a surgical instrument. As shown, theoperator removes battery pack (120) (block 2232) and removes at least aportion of casing (110) (block 2234) to expose certain internalcomponents of instrument (10, 2010), such as cam (700). The operatorthen removes motor (160, 2160), gear box (162, 2162), and cam (700) fromhandle assembly (200) (block 2236). Once these components are removedfrom handle assembly (200), the operator rotates cam (700) back to thehome position shown in FIGS. 20A and 25D (block 2238). In this regard,motor (160, 2160), gear box (162), and/or cam (700) may include amarking that is angularly positioned to indicate the home position ofcam (700) relative to the motor (160, 2160) and/or gear box (162).

Once cam (700) has been manually repositioned to the home position, theoperator then inserts cam (700), motor (160, 2160), and gear box (162)back into handle assembly (200) (block 2240) and confirms the correctposition of cam (700) relative to a reference structure (block 2242).For instance, the operator may confirm the correct position of third camfeature (730) relative to bearing member (804). If the position of cam(700) is not proper (e.g., as shown in FIGS. 20A and 25D), the operatormay further adjust the position of cam (700). Once the properpositioning of cam (700) has been confirmed, the operator replacescasing (110) (block 2244), reloads stapling head assembly (300) withstaples (90) (block 2246), and reengages the trigger lockout assembly(block 2247) to prevent undesired firing of instrument (10, 2010) untilinstrument (10, 2010) is in a state and position where it is ready to beintentionally fired. In some alternative examples, the operator mayremove cam (700) and not remove motor (160, 2160) and/or gear box (162).The operator may then replace cam (700) relative to other structures ofinstrument (10, 2010), in the position shown in FIGS. 20A and 25D.

It should be understood that after any of the processes shown in FIGS.23-24 and 26-27 are complete, instrument (10, 2010) may again be used toperform an anastomosis procedure such as the procedure shown in FIGS.21A-21E and described above. In other words, a reset instrument (10,2010) may be used just like a version of instrument (10, 2010) that hadnever been used before.

C. Exemplary Powered Reset of Manual Instrument Through Continued MotorRotation

In the examples described above, motor stop module (190) is configuredto create a short circuit and thereby prevent motor (160) from furtheractivation after paddle (806) actuates switch buttons (192) at the endof an actuation stroke (as illustrated in FIGS. 20A-20D). Some suchversions may be configured and operable in accordance with at least someof the teachings of U.S. Pub. No. 2015/0083774, issued as U.S. Pat. No.9,907,552 on Mar. 6, 2018, the disclosure of which is incorporated byreference herein. As also noted above, some such versions may allow theactuation drivetrain for stapling head assembly (300) to be returned toa home position (i.e., the state shown in FIGS. 20A and 25D) byreversing the polarity of the drive circuit to thereby cause motor (160)to rotate in the reverse direction (as illustrated in FIGS. 25A-25D).

Some alternative drive circuits may provide a different configurationand method to stop motor (160) at the end of an actuation stroke. Forinstance, some alternative drive circuits may provide a polarityreversal in the drive circuit (instead of providing a short circuit) atthe end of an actuation stroke, to thereby brake motor (160) at the endof the actuation stroke. By way of example only, such a circuit may beconstructed and operable in accordance with at least some of theteachings of U.S. Pub. No. 2017/0258471, entitled “Methods and Systemsfor Performing Circular Stapling,” published Sep. 14, 2017, issued asU.S. Pat. No. 10,709,452 on Jul. 14, 2020, the disclosure of which isincorporated by reference herein. In versions where the polarity isautomatically reversed at the end of the actuation stroke, a differenttechnique may be warranted for returning the actuation drivetrain forstapling head assembly (300) to the home position (i.e., the state shownin FIGS. 20A and 25D).

An example of a circuit (2600) providing braking of motor (160) throughpolarity reversal is shown in FIGS. 29A-29H, in which motor stop module(190) has been modified to become a motor stop module (2690). Motor stopmodule (2690) includes switch buttons (192) just like motor stop module(190). Motor stop module (2690) may also be configured and positionedjust like motor stop module (190), such that switch buttons (192) areactuated by paddle (806) at the end of an actuation stroke as shown inFIGS. 19A-19D. As described in greater detail below, switch buttons(192) are configured to provide drive circuit (2600) with a firstpolarity state (FIGS. 29A-29B and FIGS. 20A-20C) until switch buttons(192) are actuated by paddle (806) at the end of an actuation stroke;then with a second polarity state (FIGS. 29C-29F, FIG. 20D, and FIG.30A) while switch buttons (192) are being actuated by paddle (806); andthen with the first polarity state again (FIGS. 29G-29H and FIG. 30B)after switch buttons (192) are no longer being actuated by paddle (806).

FIG. 28 shows an exemplary battery pack (2500) that may be used ininstrument (10) after the completion of an actuation stroke, to returnthe actuation drivetrain for stapling head assembly (300) to the homeposition, when instrument includes a drive circuit like circuit (2600)shown in FIGS. 29A-29H. Battery pack (2500) is configured to fit insocket (116) just like battery pack (120). Battery pack (2500) alsoincludes latches (2502), just like latches (122), that releasably retainbattery pack (2500) in socket (116). Battery pack (2500) is differentfrom battery pack (120) only in that battery pack (2500) is providedwith a polarity that is the reverse of the polarity of battery pack(120).

FIGS. 29A-29H show circuit (2600) at various states of operation.Circuit (2600) includes motor stop module (2690), a pair of batteryterminals (2620, 2622), motor (160), and firing switch (2610). Circuit(2600) also includes various transistors, diodes, LEDs, and a capacitor,among other conventional components. Various kinds of components,characteristics of such components, and arrangements of such components,that may be incorporated into circuit (2600) will be apparent to thoseof ordinary skill in the art in view of the teachings herein. Batteryterminals (2620, 2622) of the present example are configured to couplewith corresponding terminals of battery pack (120) when battery pack(120) is fully seated in socket (116); and with corresponding terminalsof battery pack (2500) when battery pack (2500) is fully seated insocket (116). Motor (160) is the same motor (160) described above, suchthat motor (160) is operable to rotate cam member (700). Firing switch(2610) is coupled with firing trigger (150) such that paddle (158)causes firing switch (2610) to reach a closed state when trigger (150)is actuated; and such that firing switch (2610) is in an open statewhenever trigger (150) is not being actuated (e.g., firing switch (2610)may return to an open state after a depressed trigger (150) has beenreleased).

FIG. 29A shows circuit (2600) in a state where instrument (10) is in aninitial, ready-to use state. At this stage, battery pack (120) isdisposed in socket (116), cam member (700) is in the position shown inFIG. 20A, firing trigger (150) is in a non-actuated state, and motorstop module (2690) is providing a first polarity state. FIG. 29B showscircuit (2600) after the operator has actuated trigger (150), therebytransitioning firing switch (2610) from an open state to a closed state.As a result, motor (160) is activated to rotate cam member (700) in afirst angular direction, such that cam member (700) rotates through thestages shown in FIGS. 20A-20C.

As cam member (700) rotates through a full drive stroke, cam member(700) eventually reaches the position shown in FIG. 20D, where third camfeature (730) engages bearing member (804). As third cam feature (730)drives bearing member (804) upwardly, paddle (806) is driven to actuateswitch buttons (192), thereby causing switch buttons (192) to transitionto the state shown in FIG. 29C. Circuit (2600) is this transitioned tothe second polarity state. Upon reaching the second polarity state,motor (160) is no longer activated, such that cam member (700) stopsrotating, even if the operator continues to actuate firing trigger (150)to hold firing switch (2610) in a closed state. FIG. 29D shows circuit(2600) in a state where the operator has released firing trigger (150),thereby opening firing switch (2610), after completion of the actuationstroke.

While firing switch (2610) is shown as being in a closed state duringthe entire actuation stroke of cam member (700), and not returning tothe open state until after the actuation stroke is completed, someversions of circuit (2600) may still complete the full actuation strokeof cam member (700) even if the operator releases firing trigger (150),thereby opening firing switch (2610), before the full actuation strokeof cam member (700) is completed. By way of example only, suchfunctionality may be provided in accordance with at least some of theteachings of U.S. Pub. No. 2015/0083774, issued as U.S. Pat. No.9,907,552 on Mar. 6, 2018, the disclosure of which is incorporated byreference herein.

After reaching the state shown in FIG. 29D, the operator may wish toreturn the actuation assembly to the home state, to thereby allow theactuation assembly to run through another full actuation stroke (e.g. todemonstrate operation of the product in a training context, etc.). Tothat end, FIG. 29E shows circuit (2600) in a state where the operatorhas removed battery pack (120) and replaced battery pack (120) withbattery pack (2500). Thus, the polarity at terminals (2620, 2622) is nowreversed. With the polarity of circuit (2600) being in the second state(based on the state of switch buttons (192)), and with battery pack(2500) being inserted in socket (116), the operator may again actuatefiring trigger (150) to close firing switch (2610) again, as shown inFIG. 29F. This causes motor (160) to activate again. Unlike earlierdescribed examples where the rotation direction of cam member (700) isreversed to return to a home position, in the present example motor(160) rotates cam member (700) in the same first angular direction thatwas used during the actuation stroke shown in FIGS. 20A-20D.

FIGS. 30A-30B show cam member (700) rotating through a range of motionto transition cam member (700) from the fully actuated position (FIG.30A) to the home position (FIG. 30B). The fully actuated position shownin FIG. 30A is the same as the fully actuated position shown in FIG.20D. Also, the home position shown in FIG. 30B is the same as the homeposition shown in FIG. 20A. As cam member (700) rotates from theposition shown in FIG. 30A to the position shown in FIG. 30B, bearingmember (804) continues to ride along first surface region (732) of thirdcam feature (732) until bearing member (804) finally clears firstsurface region (732), such that bearing member (804) eventually snapsback down to the position shown in FIG. 30B. During this motion, bearingmember (804) and/or some other portion of rocker member (800) may deformto allow bearing member (804) to ride over the peak of first surfaceregion (732). Also during this motion, paddle (806) holds switch buttons(192) in an actuated state until bearing member (804) finally clears thepeak of first surface region (732).

FIG. 29F shows circuit (2600) as cam member (700) travels through therange of motion shown in FIGS. 30A-30B; and FIG. 29G shows circuit(2600) after cam bearing member (804) has cleared the peak of firstsurface region (732) such that paddle (806) is no longer holding buttons(192) in an actuated state. As shown in FIG. 29G, switch buttons (192)thereby return circuit (2600) to the first polarity state. Upon thistransition back to the first polarity state, motor (160) is no longeractivated. The operator then releases firing trigger (150), therebyresulting in firing switch (2610) returning to the open state as shownin FIG. 29H. As noted above, some versions of circuit (2600) may includea latching feature that maintains activation of motor (160) until switchbuttons (192) return circuit (2600) to the first polarity state, even ifthe operator releases firing trigger (150) and thereby opens firingswitch (2610) before cam member (700) completes the full range of traveldepicted in FIGS. 30A-30B.

After reaching the state shown in FIG. 29H, cam member (700) is returnedto the home position (FIGS. 20A and 30B), circuit (2600) is back in thefirst polarity state (due to the states of switch buttons (192)), andfiring switch (2610) is back in the open state. The operator may thenremove battery pack (2500) from socket (116) and insert battery pack(120) in socket (116), thereby returning circuit (2600) back to the sateshown in FIG. 29A. The operator may then repeat the sequence describedabove with reference to FIGS. 29A-29H as many times as desired.

III. Exemplary Combinations

The following examples relate to various non-exhaustive ways in whichthe teachings herein may be combined or applied. It should be understoodthat the following examples are not intended to restrict the coverage ofany claims that may be presented at any time in this application or insubsequent filings of this application. No disclaimer is intended. Thefollowing examples are being provided for nothing more than merelyillustrative purposes. It is contemplated that the various teachingsherein may be arranged and applied in numerous other ways. It is alsocontemplated that some variations may omit certain features referred toin the below examples. Therefore, none of the aspects or featuresreferred to below should be deemed critical unless otherwise explicitlyindicated as such at a later date by the inventors or by a successor ininterest to the inventors. If any claims are presented in thisapplication or in subsequent filings related to this application thatinclude additional features beyond those referred to below, thoseadditional features shall not be presumed to have been added for anyreason relating to patentability.

EXAMPLE 1

A method for resetting an apparatus configured for stapling tissue, theapparatus comprising: (a) a stapling head assembly, wherein the staplinghead assembly comprises: (i) an annularly arranged array of staples, and(ii) a knife with an annular cutting edge that is configured to cuttissue; (b) a shaft assembly coupled to the stapling head assembly; (c)a body coupled to the shaft assembly, wherein the body comprises: (i) amotor, and (ii) a cam member configured to rotate in response toactivation of the motor, wherein the cam member is rotatable in a firstdirection from a home position to a fired position to actuate thestapling head assembly to thereby drive the staples and the knifethrough tissue; (d) a circuit in electrical communication with themotor; wherein the method comprises: (a) providing an apparatusincluding the cam member in the fired position; (b) changing thepolarity of the circuit; and (c) activating the motor such that the cammember rotates from the fired position to the home position.

EXAMPLE 2

The method of Example 1, wherein the cam member rotates less than 360degrees when rotating between the home position and fired position.

EXAMPLE 3

The method of any one or more of Examples 1 through 2, wherein the cammember rotates through a first range of motion to transition from thehome position to the fired position, wherein the cam member rotatesthrough a second range of motion to transition from the fired positionto the home position.

EXAMPLE 4

The method of Example 3, wherein the cam member rotates in a firstangular direction during the first range of motion, wherein the cammember continues to rotate in the first angular direction during thesecond range of motion.

EXAMPLE 5

The method of Example 4, wherein the cam member rotates through a 360degrees of angular motion during a single combination of the first andsecond ranges of motion.

EXAMPLE 6

The method of Example 3, wherein the cam member rotates in a firstangular direction during the first range of motion, wherein the cammember rotates in a second angular direction during the second range ofmotion, wherein the second angular direction is opposite to the firstangular direction.

EXAMPLE 7

The method of any one or more of Examples 1 through 6, wherein thecircuit further comprises at least one polarity switch, wherein changingthe polarity of the circuit comprises actuating the at least onepolarity switch.

EXAMPLE 8

The method of Example 7, wherein the cam member is configured to actuatethe at least one polarity switch.

EXAMPLE 9

The method of any one or more of Examples 1 through 8, wherein theapparatus further comprises a trigger, wherein the motor is configuredto activate in response to actuation of the trigger, wherein the methodfurther comprises actuating the trigger.

EXAMPLE 10

The method of any one or more of Examples 1 through 9, wherein a firstbattery pack is used to activate the motor to drive the cam member fromthe home position to the fired position, wherein a second battery packis used to activate the motor to drive the cam member from the firedposition to the home position, wherein the first battery pack has afirst polarity, wherein the second battery pack has a second polaritythat is opposite to the first polarity.

EXAMPLE 11

The method of Example 10, the method further comprising: (a) removingthe first battery pack from a socket in the body; and (b) inserting thesecond battery pack in the socket in the body; wherein the act ofactivating the motor such that the cam member rotates from the firedposition to the home position is performed while the second battery,pack is in the socket in the body.

EXAMPLE 12

The method of any one or more of Examples 1 through 11, furthercomprising cleaning the instrument.

EXAMPLE 13

The method of any one or more of Examples 1 through 12, furthercomprising reloading the stapling head assembly with staples.

EXAMPLE 14

The method of any one or more of Examples 1 through 13, furthercomprising packaging the instrument in a container.

EXAMPLE 15

The method of any one or more of Examples 1 through 14, furthercomprising using the reset instrument in a surgical procedure.

EXAMPLE 16

The method of Example 15, wherein using the reset instrument in asurgical procedure further comprises using the reset instrument in ananastomosis procedure.

EXAMPLE 17

A method for resetting an apparatus configured for stapling tissue, theapparatus comprising: (a) a stapling head assembly, wherein the staplinghead assembly comprises: (i) an annularly arranged array of staples, and(ii) a knife with an annular cutting edge that is configured to cuttissue; (b) a shaft assembly coupled to the stapling head assembly; and(c) a body coupled to the shaft assembly, wherein the body comprises: asocket, (ii) a motor, and (iii) a cam member configured to rotate inresponse to activation of the motor, wherein the cam member is rotatablein a first direction from a home position to a fired position to actuatethe stapling head assembly to thereby drive the staples and the knifethrough tissue, wherein the cam member is further rotatable in the firstdirection from the fired position to the home position; wherein themethod comprises: (a) providing an apparatus including the cam member inthe fired position, wherein a first battery having a first polarity waspositioned in the socket and was used to activate the motor to therebydrive the cam member in the first direction from the home position tothe fired position; (b) inserting a second battery in the socket,wherein the second battery has a second polarity opposite to the firstpolarity; and (c) activating the motor with the second battery tothereby drive the cam member in the first direction from the firedposition to the home position.

EXAMPLE 18

The method of Example 17, wherein the apparatus further comprises atleast one polarity switch, wherein the polarity switch is positioned toplace the circuit in a first polarity state when the cam member isprovided in the fired position, wherein the polarity switch is actuatedto place the circuit in a second polarity state when the cam membercompletes a range of travel from the fired position to the home positionin response to activating the motor with the second battery.

EXAMPLE 19

A surgical kit, the surgical kit comprising: (a) a stapling instrumentthe stapling instrument comprising: (i) a stapling head assembly,wherein the stapling head assembly comprises: (A) an annularly arrangedarray of staples, and (B) a knife with an annular cutting edge that isconfigured to cut tissue, (ii) a shaft assembly coupled to the staplinghead assembly, (iii) a body coupled to the shaft assembly, wherein thebody comprises: (A) a motor, and (B) a cam member configured to rotatein response to activation of the motor, wherein the cam member isrotatable in a first direction from a home position to a fired positionto actuate the stapling head assembly to thereby drive the staples andthe knife through tissue, wherein the cam member is further rotatable inthe first direction from the fired position to the home position, and(iv) a circuit in electrical communication with the motor, wherein thecircuit is configured to transition between a first polarity state and asecond polarity state, wherein the motor is configured to drive the cammember from the home position to the fired position when the circuit isin the first polarity state, wherein the cam member is furtherconfigured to drive the cam member from the fired position to the homeposition when the circuit is in the second polarity state; (b) a firstbattery pack configured to activate the motor when the circuit is in thefirst polarity state, wherein the first battery pack has a firstpolarity associated with the first polarity state of the circuit; and(c) a second battery pack configured to activate the motor when thecircuit is in the second polarity state, wherein the second battery packhas a second polarity associated with the second polarity state of thecircuit.

EXAMPLE 20

The surgical instrument of Example 19, wherein the body further definesa socket, wherein the socket is configured to removably receive thefirst battery pack, wherein the socket is further configured toremovably receive the second battery pack.

IV. Miscellaneous

It should also be understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Theabove-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

At least some of the teachings herein may be readily combined with oneor more teachings of U.S. Pat. No. 7,794,475, entitled “Surgical StaplesHaving Compressible or Crushable Members for Securing Tissue Therein andStapling Instruments for Deploying the Same,” issued Sep. 14, 2010, thedisclosure of which is incorporated by reference herein; U.S. Pub. No.2014/0151429, entitled “Trans-Oral Circular Anvil Introduction Systemwith Dilation Feature,” published Jun. 5, 2014, issued as U.S. Pat.9,572,573 on Feb. 21, 2017, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2014/0144968, entitled “Surgical Staplewith Integral Pledget for Tip Deflection,” published May 29, 2014,issued as U.S. Pat. No. 9,289,207 on Mar. 22, 2016, the disclosure ofwhich is incorporated by reference herein; U.S. Pub. No. 2014/0158747,entitled “Surgical Stapler with Varying Staple Widths along DifferentCircumferences,” published Jun. 12, 2014, now abandoned, the disclosureof which is incorporated by reference herein; U.S. Pub. No.2014/0144969, entitled “Pivoting Anvil for Surgical Circular Stapler,”published May 29, 2014, issued as U.S. Pat. No. 9,498,222 on Nov. 22,2016, the disclosure of which is incorporated by reference herein; U.S.Pub. No. 2014/0151430, entitled “Circular Anvil Introduction System withAlignment Feature,” published Jun. 5, 2014, issued as U.S. Pat. No.9,724,100 on Aug. 8, 2017, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2014/0166717, entitled “Circular Staplerwith Selectable Motorized and Manual Control, Including a Control Ring,”published Jun. 19, 2014, issued as U.S. Pat. No. 9,532,783 on Jan. 3,2017, the disclosure of which is incorporated by reference herein; U.S.Pub. No. 2014/0166728, entitled “Motor Driven Rotary Input CircularStapler with Modular End Effector,” published Jun. 19, 2014, issued asU.S. Pat. No. 9,597,081 on Mar. 21, 2017, the disclosure of which isincorporated by reference herein; and/or U.S. Pub. No. 2014/0166718,entitled “Motor Driven Rotary Input Circular Stapler with LockableFlexible Shaft,” published Jun. 19, 2014, issued as U.S. Pat. No.9,463,022 on Oct. 11, 2016, the disclosure of which is incorporated byreference herein. Various suitable ways in which such teachings may becombined will be apparent to those of ordinary skill in the art.

While the examples herein have been provided in the context of acircular stapling instrument, it should be understood that the variousteachings herein may be readily applied to various other kinds ofsurgical instruments. By way of example only, the various teachingsherein may be readily applied to linear stapling devices (e.g.,endocutters). For instance, various teachings herein may be readilycombined with various teachings of U.S. Pub. No. 2012/0239012, entitled“Motor-Driven Surgical Cutting Instrument with Electric ActuatorDirectional Control Assembly,” published Sep. 20, 2012, issued as U.S.Pat. No. 8,453,914 on Jun. 4, 2013, the disclosure of which isincorporated by reference herein, and/or U.S. Pub. No. 2010/0264193,entitled “Surgical Stapling Instrument with An Articulatable EndEffector,” published Oct. 21, 2010, issued as U.S. Pat. No. 8,408,439 onApr. 2, 2013, the disclosure of which is incorporated by referenceherein, as will be apparent to those of ordinary skill in the art. Asanother merely illustrative example, the various teachings herein may bereadily applied to a motorized electrosurgical device. For instance,various teachings herein may be readily combined with various teachingsof U.S. Pub. No. 2012/0116379, entitled “Motor Driven ElectrosurgicalDevice with Mechanical and Electrical Feedback,” published May 10, 2012,issued as U.S. Pat. No. 9,161,803 on Oct. 20, 2015, the disclosure ofwhich is incorporated by reference herein, as will be apparent to thoseof ordinary skill in the art. Other suitable kinds of instruments inwhich the teachings herein may be applied, and various ways in which theteachings herein may be applied to such instruments, will be apparent tothose of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

We claim:
 1. A method for resetting an apparatus configured for staplingtissue, the apparatus comprising: (a) a stapling assembly; (b) a bodycoupled with the stapling assembly, wherein the body comprises: (i) amotor, and (ii) a cam member configured to rotate in response toactivation of the motor, wherein the cam member is rotatable in a firstdirection from a home position to a fired position to actuate thestapling assembly to thereby drive one or more staples through tissue;and (c) a circuit in electrical communication with the motor; whereinthe method comprises: (a) providing the cam member in the firedposition; (b) reversing the polarity of the circuit; and (c) afterreversing the polarity of the circuit, actuating a user input feature tothereby activate the motor such that the cam member rotates from thefired position to the home position.
 2. The method of claim 1, whereinthe cam member rotates less than 360 degrees when rotating between thehome position and fired position.
 3. The method of claim 1, wherein thecam member rotates through a first range of motion to transition fromthe home position to the fired position, wherein the cam member rotatesthrough a second range of motion to transition from the fired positionto the home position.
 4. The method of claim 3, wherein the cam memberrotates in a first angular direction during the first range of motion,wherein the cam member continues to rotate in the first angulardirection during the second range of motion.
 5. The method of claim 4,wherein the cam member rotates through a full 360 degrees of angularmotion during a single combination of the first and second ranges ofmotion.
 6. The method of claim 3, wherein the cam member rotates in afirst angular direction during the first range of motion, wherein thecam member rotates in a second angular direction during the second rangeof motion, wherein the second angular direction is opposite to the firstangular direction.
 7. The method of claim 1, wherein the circuit furthercomprises at least one polarity switch, wherein changing the polarity ofthe circuit comprises actuating the at least one polarity switch inresponse to rotation of the cam member.
 8. The method of claim 1,wherein the apparatus further comprises a trigger, wherein the motor isconfigured to activate in response to actuation of the trigger, whereinthe method further comprises actuating the trigger.
 9. The method ofclaim 1, wherein a first battery pack is used to activate the motor todrive the cam member from the home position to the fired position,wherein a second battery pack is used to activate the motor to drive thecam member from the fired position to the home position, wherein thefirst battery pack has a first polarity, wherein the second battery packhas a second polarity that is opposite to the first polarity.
 10. Themethod of claim 9, the method further comprising: (a) removing the firstbattery pack from a socket in the body; and (b) inserting the secondbattery pack in the socket in the body; wherein the act of activatingthe motor such that the cam member rotates from the fired position tothe home position is performed while the second battery pack is in thesocket in the body.
 11. The method of claim 1, further comprisingcleaning the instrument.
 12. The method of claim 1, further comprisingreloading the stapling assembly with staples.
 13. The method of claim 1,further comprising packaging the apparatus in a container.
 14. Themethod of claim 1, further comprising using the apparatus in a surgicalprocedure.
 15. The method of claim 14, wherein using the apparatus in asurgical procedure further comprises using the apparatus in ananastomosis procedure.
 16. The method of claim 1, wherein the cam membercomprises a first cam feature and a second cam feature, wherein the bodyfurther comprises a cam follower, wherein the method further comprises:(a) driving the cam follower in a first direction with the first camfeature to thereby actuate the staples and a knife distally; and (b)driving the cam follower in a second direction with the second camfeature to thereby retract the knife proximally, wherein the seconddirection is opposite the first direction.
 17. A method for setting anapparatus configured for stapling tissue, the apparatus comprising: (a)a stapling assembly, wherein the stapling assembly includes one or morestaples; (b) a body coupled with the stapling assembly, wherein the bodyincludes: (i) a motor, and (ii) a cam member configured to rotate inresponse to activation of the motor, wherein the cam member is rotatablein a first direction from a home position to a fired position to actuatethe stapling assembly to thereby drive the one or more staples throughtissue; wherein the method comprises: (a) providing the cam member inthe fired position, wherein a first battery having a first polarity wasused to activate the motor to thereby drive the cam member in the firstdirection from the home position to the fired position; (b) decouplingthe motor from the first battery; (c) coupling the motor with a secondbattery, wherein the second battery has a second polarity opposite tothe first polarity; and (d) activating the motor with the second batteryto thereby drive the cam member in the first direction from the firedposition to the home position.
 18. The method of claim 17, wherein theapparatus further comprises a trigger, wherein the motor is configuredto activate in response to actuation of the trigger, wherein the methodfurther comprises actuating the trigger.
 19. A method of operating anapparatus having a stapling assembly configured for stapling tissue, themethod comprising: (a) activating a motor of the apparatus to rotate acam member of the apparatus in a first direction from a home position toa fired position to thereby actuate the stapling assembly; (b)deactivating the motor when the cam member reaches the fired position;(c) reversing a polarity of the apparatus; and (d) after reversing thepolarity of the apparatus and while the cam member is in the firedposition, reactivating the motor to further rotate the cam member in thefirst direction from the fired position to the home position.
 20. Themethod of claim 19, wherein the step of activating the motor comprisespowering the motor with a first power source having a first polarity,wherein the step of reactivating the motor comprises powering the motorwith a second power source having a second polarity opposite the firstpolarity.